Simplify the following expression: $r = \dfrac{-7k - 12}{k - 1} + \dfrac{8k + 8}{k - 1}$
Explanation: Since the expressions have the same denominator we simply combine the numerators: $r = \dfrac{-7k - 12 + 8k + 8}{k - 1}$ Combine like terms: $r = \dfrac{k - 4}{k - 1}$